PCT International Publication No. WO2005/102605 (see also US2007/060030) describes a hand-held power tool that drives a detachable tool (tool accessory) interposed (clamped) between and held by a work spindle and a fastening element. This power tool is configured such that the fastening element is movable relative to the working spindle between a clamped position and an open or release position. When the fastening element is in the clamped position, the tool is fixedly secured to the work spindle, and when the fastening element is in the open or release position, the tool can be removed or detached from the work spindle. Furthermore, in the clamped position, a clamping shaft of the fastening element is held by a lock assembly inside the work spindle. The tool is held (sandwiched) between the working spindle and the fastening element by a clamping force generated by a spring element provided inside the working spindle.
In the power tool described in WO2005/102605, the fastening element moves from the clamped position to the release position by pivoting a lever toward the side of the tool. That is, in order to operate (pivot) the lever, the user's hand grasps the lever and moves it toward the tool. However, many types of tools (tool accessories) have pointed or sharp edges. Therefore, if the user's hand slips while shifting the level to the release position, it is possible that the user's hand will accidently come into contact with the sharp tool, thereby causing injury. Consequently there is a need in the art to improve the operation of the lever. For example, it would be desirable to provide an improved technology for operating (pivoting) a lever or handle when attaching and detaching a tool accessory of a power tool.